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High-resolution Scheimpflug, anterior segment OCT, and high-frequency scanning ultrasound for corneal thickness mapping: comparative study

Session Details

Session Title: Corneal biomechanics

Session Date/Time: Tuesday 08/10/2013 | 08:00-10:30

Paper Time: 08:28

Venue: Elicium 1 (First Floor)

First Author: : V.Moustou GREECE

Co Author(s): :    A. Kanellopoulos   G. Asimellis           

Abstract Details

Purpose:

To compare and correlate central corneal thickness in healthy, unoperated eyes with three advanced anterior-segment imaging systems: a high resolution Scheimpflug tomography camera (Oculyzer II), a spectral domain anterior-segment Optical Coherence Tomography (AS-OCT) system, and a high frequency ultrasound (HF UBM) system.

Setting:

Laservision.gr Eye Institute, Athens, Greece

Methods:

50 eyes, randomly selected from 50 patients were included in the study. Inclusion criteria were healthy, unoperated eyes examined consequently by the same examiner. Corneal imaging was performed by three different methods, Scheimpflug tomography (Oculyzer II), spectral domain anterior-segment optical coherence tomography (AS-OCT), and very high-frequency digital scanning ultrasound (FH-UBM). Central corneal thickness (CCT) were compared using scatter diagrams, Bland-Altman plots (with bias and 95% confidence intervals), and two paired analysis.

Results:

The Pearson coefficient of determination (R2) between Oculyzer II and AS-OCT was 0.813. Likewise, the coefficients between Oculyzer II and HF UBM were 0.872, and between AS-OCT and HF UBM, 0.657, respectively. Trend line coefficient of linearity between the Oculyzer II and the AS-OCT was 0.887, between the Oculyzer II and HF-UBM, 1.065 and 1.16, and between the AS-OCT and HF-UBM, 0.889 and 1.03. The best correlated pair was Oculyzer II and HF-UBM, with least bias (-6.90 ?m) between CCT.

Conclusions:

The three methods for corneal thickness measurements are highly correlated, particularly the Oculyzer II and the HF-UBM. Compared to the Oculyzer II, the AS-OCT seems underestimate by 10 ?m, while the HF-UMB overestimates corneal thickness by 5 ?m.

Financial Interest:

... travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented